1. Field of the Invention
This invention relates to an article and a method for making an article having one or more identification marks that function to identify information about the article, such as color, size, catalog number and the like. More particularly, the present invention is concerned with an article and a method for making an article having a laser engraved identification mark that is created by the use of a polymer coating applied to an exterior surface of the article.
2. Description of the Related Art
Laser engraving apparatus is in widespread use for marking or engraving a variety of articles. Common examples of laser engraved articles include trophies, signs, sporting goods and awards. Other laser engraved articles include product containers, musical instruments and woodcrafts.
Product containers often bear a number of identification marks that serve various purposes. Product containers commonly include at least the name of the product as well as the name of the manufacturer or seller of the product. If the nature of the product is not readily apparent, the container may also include identification marks written as text that describe in generic terms the type of product within the container.
In many instances, product containers also include a number of additional identification marks that serve other purposes. For example, the container may have marks that describe the color, shape, size, weight or volume of the product. It is also common for product containers to bear marks that identify the manufacturer""s or seller""s address, or country of origin of the product.
Many product containers also include additional identification marks that convey other information as well. For example, identification marks on product containers may include serial numbers or batch or lot codes that help identify, among other things, more detailed information to the manufacturer regarding the manufacturing process for the particular product within the container. Furthermore, identification marks on product containers may include letters or numbers that serve as catalog or product numbers for the product.
In the past, identification marks have frequently been applied to product containers using ink printing technology of one sort or another. In some instances, ink markings are applied to a label such as a label made from a section of paper or plastic film having an adhesive coating on its back side. The label is often applied to the container after the label is marked.
In other instances, ink printing technology is used to apply an ink identification mark directly on an exterior surface of the container. In that instance, the color of the ink is often selected to contrast with the color of the exterior surface of the container in order to enhance the visibility of the resulting identification mark. The identification mark may be formed as a positive image of the ink (i.e., where the ink creates letters, symbols or other indicia for identification) or as a negative image (such that the lack of ink, and hence the underlying exterior surface of the container, creates the letters, numbers or other indicia).
However, certain problems have long been associated with ink printing. For example, the operator must ensure that a sufficient quantity of fresh ink is available at all times. Also, the operator must ensure that the ink has properly hardened or cured after application so that the mark is not smudged or otherwise harmed during subsequent handling. Moreover, and particularly with ink pad printing technology, there is often a certain amount of labor, time and expense associated with efforts to switch from one identification mark to another.
In recent years, laser technology has been used to engrave product identification marks directly on product containers. Laser engraving technology presents an important advantage over ink printing technology, in that the laser engraving apparatus enables the operator to easily switch from one identification mark to another. For example, the laser engraving apparatus may include a controller that directs movement of the laser beam. In that instance, changing the identification mark is carried out by simply changing a set of computer instructions used by the controller to determine the path of the beam.
However, laser engraved identification marks on product containers are sometimes difficult to see. The ease of visibility of the mark depends on many factors, including the width of the mark and the color of the underlying container surface. The operator must also exercise caution to ensure that the energy of the beam on the surface of the container is not sufficient to burn through or otherwise unduly weaken the container, so that the strength of the container is not significantly impaired.
Laser engraved identification marks have also been used on other dental articles. For example, U.S. Pat. No. 5,322,436 describes an orthodontic band that has a laser engraved identification mark on an exterior surface. The identification mark described in that patent has a white, frosty appearance that is aesthetic and easy to read.
Known identification marks, including the marks described above, are somewhat satisfactory and are in widespread use. However, there is a continuing need to improve the state of the art. In particular, it would be desirable to provide an identification mark that is easy to read, and yet is also durable and relatively inexpensive to manufacture, even when a relatively large amount of information is to be conveyed.
The present invention relates to an article having an identification mark that combines many of the advantages of both the ink printing and laser engraving technologies described above, with the result that the identification mark is aesthetic, easy to read and relatively inexpensive. The identification mark of the present invention can be tailor-made as needed to create specific data for specific products with little human intervention. The present invention is also directed toward a method for making the improved identification mark.
In one aspect, the present invention is directed toward an article that comprises a body having an exterior surface with a certain color. A polymer coating extends over a certain region of the exterior surface. The coating has a color that contrasts with the color of the exterior surface. The article also includes a laser engraved identification mark that is formed within the coating.
Another aspect of the present invention is directed toward a method of making an article. The method includes the act of selecting a polymer coating having a color that contrasts with the color of an exterior surface of the article. The method also includes the act of applying the coating to a certain region of the exterior surface of the article. The method further includes the act of directing a laser beam toward the coating with sufficient power to cause the coating to undergo a chemical reaction and create an identification mark.
These and other aspects of the invention are described in more detail below and are illustrated in the accompanying drawings.